The traditional public switched telephone network (PSTN) is generally considered to be secure, particularly systems which communicate over land lines.
In recent years, however, voice networks have become deregulated and providers have been forced to open their networks to outside companies. New methods of integrating voice communication with packet networks have been developed. Protocols, such as voice over IP (VOIP), have been investigated primarily as a way of reducing long distance charges conventionally associated with switched voice communications. Packet networks, and in particular the ubiquitous Internet, is known to rely on open concepts which have resulted in hackers and the like breaking into packet networks either maliciously or for some gain. Considerable effort has been spent in developing security systems which will offer some degree of security to packet networks. The integration of traditional switched voice communications with packet networks opens the door for security issues which are of particular concern to high end customers including the military, large corporations and in particular financial institutions. To date, however, there does not appear to have been any developments in the area of signaling security for switched telephone networks (eg. PSTN).
Packet networks in general are known to be moving towards secure protocols utilizing encryption and cryptographic authentication techniques, but to date the same hasn't been observed in traditional voice networks.
Systems also exist for use in connecting switched voice networks to packet voice networks. An example of one such system is the Alcatel 5070 SSG which provides a gateway between the SS7 protocol of the switched networks and a protocol such as SIGTRAN which implements the SS7 protocol over an IP packet network. The Alcatel 5070 SSG allows for signaling traffic from the switched networks domain through traverse packet networks and vice versa.
VPN gateways are typically used to terminate secure IP SEC or SSL protocols in IP networks. These protocols can provide secure and strong cryptographic authentication and encryption of network traffic. It is, accordingly, a principal object of the present invention to apply such authentication and encryption techniques to a switched voice network environment.